Plato, I've made a few fruit wines and a hard cider, once they are fermented to dry, they are bitter until we back sweeten, all of the sugar that we had tasted prior to fermentation has fermented and has been converted to alcohol.
An SG of 1.010 fermented down from 1.090 would give you an Alcohol by Volume of 10.48%, not too bad, but still near the alcohol of a wine, but.....you added sugar to the secondary, and the wine was most likely not fermented to dry, therefore, it is possible that the yeast was able to ferment the added sugar as well.
The 2 pounds of sugar you added to this 5 gallon batch of apple wine, increased the potential alcohol of the wine by roughly 2 percent, if the yeast was able to ferment it, this would have raised your ABV to nearly 12-13%. You've entered the realm of hard cider at that ABV%
In a light fruit wine such as an apple wine, this can taste "hot" or bitter until it ages and mellows out.
We usually add the sugar to the fermenting bucket to raise up the SG to increase the final alcohol content, this way we can monitor the SG with our hydrometer and know when fermentation is finished and stabilize the wine, add sorbate to stop any further fermentations and back sweeten, then bulk age.
You said that:
I then waited on it to clear out and added the Campden Tablets and Potassium Meta.
As Morgan stated, these are one in the same, although it isn't a great thing to do, depending on how much sulfite was added between the two, you could reduce the Sulfites by stirring in oxygen (stirring in oxygen isn't normally a good thing for wines).
I would add Potassium sorbate, and back sweeten to your taste and let sit for a week or so and see if that helps the taste at all.
If it is very acidic, we can help with that as well.
I hope that this helps,
Tom